In the Sumerian city, the Ziggurat of Ur stood a skyscraper over the city. It was about 20 metres (66 feet) tall.[3] Later the ziggurat became more than a place for gods. There were workshops for craftworkers. For the priests, they were temples to do worship. There were big staricases to get up and down. The only level that remains today is the bottom. They tell a lot about the people who built them. Sumerians had no tools and machinery like us. They were careful brick builders. Brickmakers formed mud bricks there were perfect. After drying they take them to the site and set them in place with bitumen. Bitumen is a thick sticky black stuff. It's like asphalt, the stuff they use to pave roads. They braided reeds so they would be stronger, and hooked them up like steel cables.

Ur had three social classes. The richer, like government officials, priests, and soldiers, were at the top. The second level was for merchants, teachers, laborers, farmers and craftmakers. The bottom were for slaves captured in battle. Burials at Ur give insight into people's social standing. Kings and queens were buried with treasure. Rich people were buried with less. Since irrigation gave Ur abundant crops, not everybody needed to work on farms. People learned other skills. Sir Leonard Woolley found a tablet that listed Ur's special workers. The chisel workers made sculptures, the gem cutters made gems, and the fullers stomped on woven wools to make them soft. The metal workers made weapons. Cities have different groups. Some of the richer people are more powerful.